Embodiments of the present invention provide a method and an apparatus for acquiring 3D format description information. The method includes: receiving an out-of-band message that carries 3D format description information and is sent by a sending end, where the out-of-band message is received before a client participates in a multimedia session initiated by the sending end; and parsing the out-of-band message and acquiring the 3D format description information from the out-of-band message. In the method and the apparatus for acquiring 3D format description information according to the embodiments of the present invention, a client is capable of acquiring 3D format description information before a video is acquired, so that the client may determine, before the video is received, whether the client matches a format used for a 3D video. This improves the speed of determining the match, reduces the overhead of receiving and processing the video, decreases electric power consumption, and alleviates the burden on a receiving device.